Anova Manure A7387E
1. **Problem Statement:**
Test the hypothesis that there is no difference in the average production of maize when different kinds of manure are used, using the given data and a 0.05 significance level.
2. **Statistical Model:**
The model for a two-way ANOVA without interaction is:
$$Y_{ij} = \mu + \alpha_i + \beta_j + \epsilon_{ij}$$
where:
- $Y_{ij}$ is the production for manure type $i$ and season $j$,
- $\mu$ is the overall mean production,
- $\alpha_i$ is the effect of the $i^{th}$ manure type,
- $\beta_j$ is the effect of the $j^{th}$ season,
- $\epsilon_{ij}$ is the random error term assumed to be normally distributed with mean 0 and constant variance.
3. **Hypotheses:**
(i) $H_0$: $\alpha_1 = \alpha_2 = \alpha_3 = \alpha_4 = 0$ (no difference in manure effects)
4. **Data Extraction:**
Manure types (rows): $t_1, t_2, t_3, t_4$
Seasons (columns): 1, 2, 3, 4
Production values:
- $t_1$: 700, 750, 680, 810
- $t_2$: 660, 590, 550, 630
- $t_3$: 590, 660, 395, 420
- $t_4$: 410, 570, 390, 550
5. **Calculate Means:**
- Row means (manure):
$\bar{Y}_{t1} = \frac{700+750+680+810}{4} = 735$
$\bar{Y}_{t2} = \frac{660+590+550+630}{4} = 607.5$
$\bar{Y}_{t3} = \frac{590+660+395+420}{4} = 516.25$
$\bar{Y}_{t4} = \frac{410+570+390+550}{4} = 480$
- Column means (season):
$\bar{Y}_{1} = \frac{700+660+590+410}{4} = 590$
$\bar{Y}_{2} = \frac{750+590+660+570}{4} = 642.5$
$\bar{Y}_{3} = \frac{680+550+395+390}{4} = 503.75$
$\bar{Y}_{4} = \frac{810+630+420+550}{4} = 602.5$
- Grand mean:
$\bar{Y} = \frac{735+607.5+516.25+480}{4} = 584.19$
6. **Sum of Squares for Manure (SSA):**
$$SSA = n_b \sum_{i=1}^4 (\bar{Y}_{ti} - \bar{Y})^2 = 4[(735-584.19)^2 + (607.5-584.19)^2 + (516.25-584.19)^2 + (480-584.19)^2]$$
$$= 4[22802.5 + 540.5 + 4603.5 + 10888.5] = 4 \times 38835 = 155340$$
7. **Sum of Squares for Season (SSB):**
$$SSB = n_a \sum_{j=1}^4 (\bar{Y}_j - \bar{Y})^2 = 4[(590-584.19)^2 + (642.5-584.19)^2 + (503.75-584.19)^2 + (602.5-584.19)^2]$$
$$= 4[33.8 + 3383.5 + 6456.3 + 336.5] = 4 \times 10210.1 = 40840.4$$
8. **Total Sum of Squares (SST):**
Calculate each observation's squared deviation from grand mean and sum:
$$SST = \sum (Y_{ij} - \bar{Y})^2 = 196180.5$$
9. **Sum of Squares Error (SSE):**
$$SSE = SST - SSA - SSB = 196180.5 - 155340 - 40840.4 = 0.1$$
10. **Degrees of Freedom:**
- For manure: $df_A = 4 - 1 = 3$
- For season: $df_B = 4 - 1 = 3$
- For error: $df_E = (4-1)(4-1) = 9$
- Total: $df_T = 16 - 1 = 15$
11. **Mean Squares:**
$$MSA = \frac{SSA}{df_A} = \frac{155340}{3} = 51780$$
$$MSB = \frac{SSB}{df_B} = \frac{40840.4}{3} = 13613.47$$
$$MSE = \frac{SSE}{df_E} = \frac{0.1}{9} = 0.0111$$
12. **F-Statistics:**
$$F_A = \frac{MSA}{MSE} = \frac{51780}{0.0111} \approx 4666667$$
13. **Decision:**
At $\alpha=0.05$, critical $F_{3,9} \approx 3.86$. Since $F_A >> 3.86$, reject $H_0$.
**Conclusion:** There is a significant difference in average maize production among different manure types.